At present, machines for lining cups or other containers by ejecting, reversing and positioning hygienic caps so that the caps adhere perfectly and line both the inside and the rim of the cups, are not available.
A hygienic cap is disclosed in Italian patent no. 01268455, and its sucessor patent application PCT/IT94/00172, the cap being positioned in the cup manually by putting it inside and pushing it down so that the hygienic cap adheres perfectly, lining the inside of the cup. According to the patent and the PCT application, the cup or similar container has a hole in the bottom so that all the air can flow out when the cap is pressed inside, thus obtaining perfect adherence and optimal lining.
The operation of lining, which hygienically isolates the cup to prevent direct contact between the container and the substance it contains and the user's lips, is, however, awkward and not completely hygienic as the cap touches the supporting surface and so protection becomes less effective.